[lhorie]

I wrote about that (and the drawbacks and alternative takes) here: https://news.ycombinator.com/item?id=16540223 but yes, in a nutshell, "move the problem from dom-diffing to map-diffing" is basically what a reactive system is supposed to be taking care of.

You're absolutely right that reactive systems are not trivial to implement (let alone implement well), but inefficient DOM recreation under these systems is a symptom of poor granularity in the reactive layer (which may be a problem with the reactivity library just as well as it could be poor usage of its API), rather than a limitation of the rendering library itself.

[amelius]

Ok, that makes sense.

I'm also worried about debugging accidental dependency triggers. Imagine that suddenly the scroll-state of some div is reset; how do you determine which dependency caused the DOM element to be recreated? With a vdom you avoid the whole problem.

[lhorie]

> how do you determine which dependency caused the DOM element to be recreated

Normally, I would toss in a throw and look at the stack trace. But yes, the stack trace gets noisy as hell.